Its Annual survey of hours and earnings, 2013 provisional results, found that, for the year ending 5 April 2014, full-time earnings for men stood higher than women at £558 per week compared to £462.

The gap between male and female earnings from 1997 to 2014 has remained relatively consistent at around £100, but this corresponds to a faster rate of increase for women than men over this period. There has been a 74% increase for women compared with 56% for men, meaning that the gap has been closing in percentage terms.

In April 2014, the gender pay gap for the private sector decreased from 19.2% to 17.% but the gap in the public sector increased from 9.5% to 11%.

The research also found that, in April 2014, median gross weekly earnings for full-time employees were £518, up 0.1% from £517 in 2013.

Median gross annual earnings for full-time employees, who had been in the same job for at least 12 months, were £27,200, an increase of 0.7% on the previous year.

It also found that median gross weekly earnings for full-time employees were highest in London, at £660, and lowest in Northern Ireland.

Nicky Morgan, minister for women and equalities, said: “I am delighted that the gender pay gap has reduced to its lowest point in history. However, there is more to be done and the government will continue to work with industry to make sure it reduces even further.

“Women are vital to the success of our long-term economic plan and we need to make the most of their skills at every age. We have more women in work than ever before, but businesses need to value diversity in their workforce and pay attention to the role of women in their organisations.”

Frances O’Grady, general secretary of the Trades Union Congress, added: “It’s good to see the gender pay gap narrowing again. But, after last year’s widening, we’re only back to where we were in 2012.

“Part-time women’s pay still lags some way behind that of their full-time colleagues. The full-time gender pay gap may have closed for younger women but it widens dramatically for women in their 40s and 50s.

“Far too many women still find they have to take a step down to access flexible or reduced hours once they become mothers, and their earnings never recover even when they return to full-time work.”

Geraint Johnes, director at Lancaster University’s Work Foundation, said: “The data shows that the proportions of workers being paid less than the relevant minimum wage is markedly higher for young workers, aged 16-20, than is the case for those aged 21 or more.

“For the latter group, well under 1% are paid below the minimum, but for younger employees the proportion is between 2.5 and 3%. In total, some 236,000 workers receive a wage below the minimum, of whom 40,000 are aged between 16 and 20.”